I’ll start…
I have Reviewer status, though I typically limit my contribution to discussions, with an occasional “proper” Review and Approval. I’m considering getting more involved because we’re approaching triple digits on the number of outstanding PRs. I made my first Merge yesterday on a minor PR, to see what the process was, and considering I may be able to help bring the number of approved but unmerged PRs down.
But I’ve had some lingering questions…
- It would be helpful to know if there is any understanding of who can perform merges. I have always assumed it was contributors with “Trusted Reviewer” status. But I see that list is very short and we obviously have more people making merges than that.
- Is there a process to perform between a PR being Approved and it being Merged? For example, a grace period for other interested people to have eyes on it that may have been away during the review.
- Is there any particular communication with the Release Manager before/while performing merges?
- Can someone relay their experience with performing Merges, any preparatory work/organizing, things to look out for, common mistakes, etc.
Also, a rough hand count of people currently willing to perform both Reviews and Merges would be helpful.
I should mention this comes after a long line of comments on the stagnant state of moving PRs over the finish line, which has been discouraging for some (one example on this forum). There’s been an encouraging uptick in discussion on PR threads though. 
One concern is that some of these approved PRs should spend some time in circulation in the dev build for testing, rather than waiting for a release push when a couple dozen changes will flood the develop branch.